Fig. 2.

Schematic of the detection principle of high-sensitivity in situ hybridization. The common underlying mechanism of these highly sensitive in situ hybridization methods is to use multiple short oligonucleotides as primary probes and then hybridize the probes for amplification, using part of the primary probes as a linker. A: RNAscope, B: HCR in situ hybridization, C: clampFISH, D: SABER FISH. E: Example of high-sensitivity in situ hybridization image. Transcripts of the membrane receptor Npffr1 gene in the rat hypothalamus were visualized by RNAscope (magenta) in combination with immunostaining for kisspeptin (green). Bar = 50 μm. 3V, third ventricle.